1. Field of the Invention
The present invention relates to a brick made of refractory material. More particularly, the invention relates to formed bricks that can be used as parts of construction elements in a furnace for calcining carbon bodies, where at least one of the surfaces of the bricks is provided with mating or interlocking elements. The mating elements cooperate with complementary mating elements in an adjacent brick.
2. Discussion of Related Art
WO 97/35150 relates to a design of refractory bricks to be used in a ring chamber furnace where the upper surface of the brick is provided with an arrangement of mating elements shaped as an elongated groove extending lengthwise along the complete length of the brick, together with crosswise extending grooves terminating short of the sides of the brick. The lower surface of the brick is formed in a similar manner with complementary projections that cooperates with a similar, underlying brick.
The system as described above has a rather complicated geometry that involves high costs related to production/maintenance of production tools in the manufacture of such bricks. Further, a system of grooves/tongues extending along the complete length of the brick could possibly involve a risk of leakage of gas through the wall, as a result of gas leakage through the layers between adjacent bricks. Particularly in calcining furnaces, such leakages may generate problems with respect to burn-off in carbon bodies caused by air entering the chamber where the calcining process takes place. Another problem related to longitudinal grooves/tongues extending approximately along the complete length and width of the brick, is that such grooves/tongues may represent regions of tension concentration where weakening lines or crack formation may occur, which in a worst case may indicate that the brick is cracking wholly or partly, leading to leakages or weakening of the overall wall construction.
FR 2 415 279 discloses a refractory brick for use in a furnace where the brick has mating elements, such as projections, at is upper surface and recesses in its lower surface. The mating elements may be circular and have the shape of a cut-off cone.
The present invention relates to refractory brick for use in a calcining furnace of the calcining of carbon bodies. In such a furnace, the brick work will be exposed to great cyclic temperature variations, typically from room-temperature and up to about 1250xc2x0 C. Such cycles may introduce tension forces in the brick work and initiate creeping, in particular, during the course of time. Bricks in accordance with the present invention has so far shown promising results with respect to endurance and stability.
With the present invention, a novel design of a brick where the above mentioned disadvantages can be avoided is achieved. The brick in accordance with the invention can be manufactured at low costs, as the shaping tool used in the pressing of the brick before burning has a simple and rugged geometry. Further, the geometric shape of the brick makes possible to reduce the number of different types of bricks that are included in a calcining furnace. The fact that this number can be reduced indicates that the logistics with respect to maintenance and repair work can be simplified, and that the constructional drawings of the furnace can be simplified. Following this, the construction period for a furnace can be reduced.